1. Field
The following description relates to a speech recognition apparatus and method.
2. Description of Related Art
Generally, in automated speech recognition, words are recognized as a sequence of phonemes defined in a pronunciation dictionary. Thus, in such a speech recognition technology, a speech recognition result is represented by a sequence of phonemes, e.g. as basic linguistic units, present in the pronunciation dictionary, and hence, if a word is not defined in the pronunciation dictionary, it is regarded as being out of vocabulary (OOV) and cannot be recognized by the speech recognition device.
If the number of words in the pronunciation dictionary is merely indefinitely increased in an attempt to address the above problem, the speech recognition efficiency of the speech recognition device becomes reduced as the amount of resource use increases dramatically. For these reasons, the number of words in the dictionary is generally limited to up to a million words.
However, in such speech recognition device, when the number of words in the pronunciation dictionary is restricted, words that are not defined in the pronunciation dictionary cannot be recognized. Thus, there are technological problems associated with such speech recognition devices.